Method of repairing stringers



May 12, 1936 A. G. LEAKE METHOD OF REPAIRING STRINGERS Filed July 15, 1952 Patented May 12, 1936 UNITED STATES PATENT OFFICE METHOD OF REPAIRING STRINGERS Arthur G. Leake, Bridgeport; Conn. Application July 15, 1932, Serial No. 622,596

4 Claims. (01. 189-37) This invention relates to new and useful improvements in means and method of strengthem mg and repairing structural members and particularly the top chords of the stringers of railroad bridges.

Annbject of.the invention is to provide a means and method which may be used for repairing the top chords of the stringers of .railroad bridges when said chords have cracked under repeated cross bending stresses and which may be used for strengthening or reenforcing such top chords against repeated cross bending .stresses when railroad car trucks pass over cross ties supported by such chords.

Another object is to provide a method and means as stated and which may be employed for the repairing or strengthening of the top chords of stringers while such stringers are in a bridge structure and while the bridge is in use and without interfering with traffic over the bridge.

Other objects and advantages will become apparent from a consideration of the following detailed description taken in connection with the accompanying drawing wherein a' satisfactory embodiment of the invention is shown. However, it will be understood that the invention is not limited to the details disclosed but includes all such variations and modifications as fall within the spirit of the invention and the scope of the appended claims.

In the drawing:

Fig. 1 is a longitudinal sectional view through a portion of a bridge, the top chords of the stringers of which have been repaired or strengthened according to the present invention, the view being taken substantially along the line l--l of Fig. 2;

Fig. 2 is a plan view showing a portion of a bridge reenforced or repaired in accordance with the present invention;

Fig. 3 is a transverse sectional view taken substantially along the line 3-3 of Fig. 1;

Fig. 4 is a side elevational view of a portion of 4 a reinforced stringer the view being on an enlarged scale;

Fig. 5 is a sectional view along the line-55 of Fig. 4;

Fig. 6 is a view looking from the underside of Fig. 4;

Fig. 7 is a front elevational view of a bracket employed;

Fig. 8 is a side elevational view of the bracket; and

Fig. 9 is a bottom plan view of the bracket.

Referring in detail to the drawing, at In is shown a portion of a railroad bridge including stringers ll supported betwen'cross girders I2 and directly supporting railway cross ties l3 on which are mounted rails H. The stringers I l are of usual construction and each includes a web I5 and top and bottom or upper and lower chords l6 and I1. Chords l6 and Il are shown as in the form of angle irons, each chord comprising two angle irons ordinarily riveted to the web l5; as at l8.

The stringers described are of a common con 10 struction and in use the top chords I6 may become cracked due to the repeated bending loads as the car trucks pass over them, and also deteriorate and become weakened due to corrosion. In using other methods of repairing stringers here- 15 tofore it has been necessary to remove the continuous top cord angle l6 on each side by cutting out the rivets. Then new cord angles were riveted in place. To do this it was necessary to stop traffic and jack up the ties and rails. According to the present invention a means and a method are provided whereby these chords may be repaired or strengthened without jackingup the cross ties ofi the stringer and in fact without in any way interfering with the normal use of the bridge. That T is, the cords I6 of the stringers are repaired or strengthened without removing the stringers from the bridge, and it will therefore be appreciated that the invention may be economically practiced.

In practicing the invention brackets 19 are 30 employed and these brackets maybe constructed in a shop and transported to the bridge to be strengthened or the parts for the bracket may be assembled in the field. Each bracket l9 includes a top plate 20, a rear plate 2| and a connecting 35 web 22. The web 22 is preferably substantially in the form of a right-angled triangle, and to the base edge of the web there is secured the top plate 20. The plate 20 is so arranged as to project at each side of the web 22 and the said plate and web are welded together as at 23. To the rear or upright edges of the web 22 the rear plate 2| is applied and ,this plate is welded to the web as at 24. It will also be noted that the plate 2| is shown as projecting at each side of the web 22 and it will further be noted that this plate is disposed against the rear edge of the we.) so as to have its rear surface spaced from but parallel to the plane of the rear edge of the web. The purpose of this particular construction will later appear.

Before the brackets l9 are applied to the stringer or stringers any cracks in the top chords are welded upand the under surfaces of the chords should be cleaned off to remove scale and the like. Next, a bracket I9 is disposed against the stringer with the top plate 20 of the bracket engaging the under surface of a top chord of the stringer and with the rear plate 2| of the bracket disposed against the web of the stringer. The top and rear plate are then welded to the under side of the chord I6 and to the web l respectively of the stringer the welding taking place about the edges of the plates as shown at 25 and 26 respectively. When one bracket has been thus applied the next bracket is disposed against and weldedto the stringer as already described. The rear plate 2| of the bracket is of at least the thickness of the portion of the chord at the side of web l5 and thus will engage the said web when the rearedge of the bracket web 22 engages the depending arm of the angle iron forming the chord. The edge ofweb 22 may be welded to the angle I6 if desired.

A series of brackets may be thus applied to one side of a stringer and then a series may be applied to the opposite side thereof as disclosed most clearly in Figs. 2 3, 4 and 5. Attention is directed to the fact that the brackets are so arranged that their web portions 22 are disposed in successive top plates are arranged quite close to one another.

While welding these plates to the chords l6 sufiicient welding material may be used at the ends of the plates to fill in the spaces between the ends.

Particularly by reference to Fig. 1 it will be noted that according to the present invention the entire top chord of a stringer is strengthened or reenforced and what in fact amounts to a new top chord is applied to the stringer. Since the ends of the plates 20 are welded together they in effect provide a continuous plate at the underside of the top chord of the stringer whereby such chord is strengthened for its whole length. of course, if desired, one or two brackets might be applied for the purpose of strengthening a particularly weak point without strengthening the entire stringer.

As all of the work in applying the brackets is done from the underside of the bridge it will be noted that the workmen are not hampered by traflicpassing over the bridge and that the strengthening of the bridge takes place without the necessity of tearing up the track or removing the stringers from the bridge and without delay to traffic passing over the bridge. It will, therefore, be apparent that the present invention provides a very economical method of repairing or strengthening the stringers of bridges.

In applying the brackets one or two or a whole series of brackets may be positioned on the load from the chord to stringer and held in place in any suitable manner as by removable clamps or the like. Next the welding operations take place and when ap-v plying a bracket the top plate 20 and then the rear plate 2| may be welded to the stringer or if desired the order of welding the plates to the stringer may be reversed.

Having thus set forth the nature of my invention, what I claim is:

1. A reinforced stringer of a railroad bridge including an upright web and a laterally extending top chord connected therewith, a top strengthening and bearing plate welded to the underside of the chord, a rear bearing plate welded to a face of the web below the chord, and an upright web plate welded at its upper edge to the under surface of the top plate and at its rear edge to the outer surface of the rear plate to transfer load from the chord to the web.

2. A reinforced stringer of a railroad bridge including an upright web and a laterally extending top chord connected therewith, a series of top plates welded to the underside of the cord and substantially end to end with-the ends of adjacent plates welded to each other and to the chord, an upright web plate welded at its top edge to the underside of each top plate, and a rear plate welded to the rear upright edge of each web plate and with its edges welded to the face of the upright web of the stringer below the chord to form a bearing for the web plate on the stringer web to distribute load from the chord to the web.

3. A re-enforced stringer of a railroad bridge including an upright web and a laterally extending top chord connected therewith. a top strengthening and bearing plate welded to the under side of the chord, a rear bearing plate welded to a face of the web below the chord, and an upright web plate welded at its upper edge to the under surface of the top plate substantially mid-way the ends thereof and at its rear edge to the outer surface of the rear plate substantially midway the ends thereof to transfer the load from the chord to the web.

4. A re-enforced stringer of a railroad bridge including an upright web and a laterally extending top chord connected therewith, a series of top plates welded to the underside of the chord and substantially end to end with the ends of adjacent plates welded to each other and to the chord, an upright web plate welded at its top edge to the under side of each top plate substantially inid-way the end thereof, and a rear plate welded substantially midway its ends to the rear upright edge of each web plate and with its edges welded to the face of the upright web of the stringer below the chord to form a bearing for the web plate on the stringer web to distribute the web.

ARTHUR G. LEAKE. 

